Answer: Dakota was less than 51 inches last summer.
Step-by-step explanation: First of all let us represent Dakota's height last summer by letter x.
The height requirement for the roller coaster is given as 54 inches. This means Dakota must be 54 inches or higher in order to be allowed on the ride. However, Dakota is too short to ride. This can be represented mathematically as x < 54.
If However, last summer Dakota grew 3 inches taller, then we can also represent this mathematically as x + 3 < 54.
To solve for this;
x + 3 < 54
Subtract 3 from both sides of the inequality
x < 51. (That is x is less than 51)
Since Dakota's height has been represented by x, we can now interpret this inequality as;
Dakota was less than 51 inches tall last summer.